As price of copper become higher and higher, thus the cooper is being replaced with aluminum gradually in electromotor industry. However, aluminum wires have a lot of disadvantages such as weak flexibility, easy to be oxidized and hard to be welded compared with copper wires. Conventionally, when connecting the enameled aluminum wire with other wires or connection terminals, a lacquer coat thereof is removed by physical method or chemical method firstly, and then the connection between the enameled aluminum wire and other wires or connection terminals is carried out. Chinese patent application No. 200920018676.8 discloses an inductive element for enameled aluminum wire winding which includes a framework and an enameled aluminum wire. And the enameled aluminum wire winding is made by connecting a head portion of the enameled aluminum wire with a leg having solidification solder.
However, this method brings several problems. Firstly, as the lacquer coat at the connection part or welded part has been removed so that the aluminum wire is exposed in the external air and will be oxidized easily. Moreover, corrosion of the aluminum wire will become much severe under the impact of the external environment, which causes the aluminum wire becomes stiffen and brittle. When the electromotor is on operation, the connection part and neck portion of the aluminum wire are easy to be broken and cracked as the electromotor shakes, which may shorten the life of the enameled aluminum wire. Secondly, due to the corrosion of the aluminum wire at the connection part or welded part, the resistance of the aluminum wire at the connection part or welded part will become larger which causes the corresponding part generate heat and then aggravate the oxidation of the aluminum wire, furthermore causes a fire on the aluminum wire when it overheats. Thirdly, as shakes may be generated during the operation of equipments having the enameled aluminum wire winding such as electromotor, transformer, relay or solenoid, thus the connection part may be disengaged with the leg under the shakes.
Thus, there is a need for a safe and timeproof enameled aluminum wire winding with a stable structure and a preparation method thereof to overcome the drawbacks such as easy oxidization, cracking and the like.